Reciprocable combustion engine



May 14, 1963 K. E. MANN 3,089,735

RECIPROCABLE COMBUSTION ENGINE Filed May 5l, 1961 5 Sheets-Sheet 3 F/G.a 2 fl/ 7 F/G. /0 7 I United States Patent O 3,089,735 RECIPROCABLECOMBUSTION ENGINE Karl Ernst Mann, Meinerzhagen, Westphalia, Germany,

assignor to Otto Fuchs Kommandit Gesellschaft, Memerzhagen, Westphalia,Germany Filed May 31, 1961, Ser. No. 113,892 Claims priority,application Germany June 2, 1960 19 Claims. (Cl. 308-23) rllhe presentinvention relates to reciprocable combustion engines, and particularlyto engines hav-ing a motor block cast of light metal alloys.

Motor -blocks produced of light metal alloys possess several advantagessuch as low specific gravity, high heat conductivity and others known inthe art.

However, particularly after prolonged use, such light metal engines willnot operate Ia-t the desired low noise level. It has been ffound thatthe lit between the crank shaft and the bearings supporting the samewill be subject to progressive deterioration, the play between crankshaft and bearing will increase and the bearing will becomeout-of-round.

It has been attempted to redu-ce the noise caused by the above describedconditions .by forming in the bearing a relatively thick film of oil.However, the results obtained in 'this manner were not satisfactory,partly due to the fact that the viscosity of the lubricating oildecreases with increasing temperatures.

Recently attempts 4have been made to cope with this problem byconsidering the difference in the heat expansion coeliicients o-f themetals and alloys involved. Within the temperature range relevant forthe operation of combustion engines, the light metal alloy of the motorblock might exp and at Ia greater rate than the bearing shell or thecrank shaft. The thus caused change in the degree of play depends onvariations of the prevalent temperature and thus is reversible. In thisconnection it has been suggested to machine the bearing to the lowerlimit and the lbearing contacting crank shaft portions to the upperlimit of the permissible tolerance. It has also been suggested to solvethe problem of different heat expansion coeiiicients of the variousmetal parts involved by providling a bimetallic bearing cap capable .ofcompensating for the heat expansion of the bearing.

However, all of these attempts met only with limited success.

It is therefore an object of the present invention to overcome the abovediscussed diiilculties Iand disadvantages connected with the use oflight metal motor blocks in reciprocable combustion engines.

It is another object of the present invention to provide a reciprocablecombustion engine having a light-metal motor block, wherein even Iuponprolonged use the play in the crank shaft bearings will not exceedtolerable limit-s.

It is a furtherlobject of the present invention to provide a light metalreciprocable combustion `engine which may be operated for prolongedperiods o-f time without substantial increase in engine noise.

Other objects and advantages of the present invention will becomeapparent from a )further reading of the de- K 3,089,735 Patented May 14,1963 into the cylindrical recess in the bearing insert, whereby pressureexerted by a crankshaft on the bearing shell will be distributed upon -asurface tarea of the cast motor block which is greater than the area ofcontact between the bearing insert and th'e bearing shell.

According to a prefer-red embodiment of the present invention, the'bearing support structure for reciprocable combustion engines Iand thelike comprises, in combination, a moto-r .block of cast light metal, acrank shaft, bearing means 4for supporting the crank shaft, extrudedfirst support means of magnesium alloy idirectly carrying the bearingmeans land having sa bearing contacting surface of predetermined area,themagnesium Ialloy yof the extruded lirst support means having ananisotropic grain structure, and second support means for-ming part ofthe motor block for carrying the first support means, the first supportmeans having a downwardly directed .face in contact with the secondsupport means and having a square yarea which measured in horizontaldirection equals at least twice the cross-sectional area of the bearingsupported portion of the crank shaft taken in horizontal direction andthrough the center thereof so that pressure exerted by the crank shafton the bearing will be distributed upon a surface area of the secondsupport means which is `greater than the predetermined contact surfacearea between the bearing and the first support means, the compressionyield strength of the first support means Vbeing lgreater th-an thecompression yield strength of the Vcoefficients of the various coactingmetal par-ts. Consequently, any attempts to equalize heat expansion orto make allowance for the differences in vheat expansion of the variousparts will, at most, meet only with limited success.

The present invention is based on the surprising nding that the majorreason of the above discussed diiiiculties are not so much due to thedilferential heat expansion but to the stress exerted during'operationof lthe engine on the bearing shell and by the bearing shell on thesupporting portion of the light metal motor block. It is the ability orinability of the affected parts to withstand the impact stress whichmainly controls the play and the degree of out-of-round condition of thebearing, .and thus the noise level.

Due to the impact stress exerted by the crank shaft on the bearing shelland the supporting portion of the light metal motor block, anirreversible increase in the play between crank shaft and bearing shellwill Abe created, and this in turn will bedue to the fact that due tosuch stress during prolonged oper-ation of the engine a plasticdeformation of the bear-ing shell supporting portion of the light metalmotor block occurs.

The compression yield strength of light met-a1 casting alloys isrelatively low. Such compression yield strength (00,2) is the pressureexpressed in kilograms per square millimeter yby which a permanentdeformation of 0.2% is obtained. Thus, for instance, the compressionyield strength of the magnesium alloy AZ91, containing about 9%aluminum, 1% zinc and 0.15% manganese, is about 11 kg./mm.2. Thecompression yield strength of a eutectic aluminum-silicon alloy is aboutkg./mm.2. 'Ihe above values were determined on specially cast testingrods and thus are better than the actual values of cast bodies such asmotor blocks wherein irregularities such as pipings hardly can beavoided.

Other light metal casting alloys also have a relatively low compressionyield strength. Thus, an aluminum alloy containing between 5 and 13%silicon and at least one of the metals copper, magnesium and manganesein quantities of up to 4% copper, up to 1% magnesium and up to 1%manganese, will have a compression yield strength of about 6.5 kga/mm?.The compression yield strength of magnesium casting alloys containingbetween 510% aluminum, up to 4% zinc and between 0.1 and 0.5% manganesewill hardly exceed 13 kg./mm.2.

According to the present invention it is now proposed to eliminate or atleast substantially reduce crank shaft bearing deformation and increasein play between crank shaft and bearing by interposing an insert betweenthe bearing shell and the light metal motor block, which insert or firstsupport means according to certain preferred embodiments of the presentinvention will consist of an alloy the density of which has beenincreased by kneading deformation. In any event, the insert according tothe present invention must possess a greater compression yield strengththan the light metal alloy of the motor block, and the shape of theinsert will be thus that the stress exerted by the crank shaft will bedistributed over a greater area of the motor block than would be thecase if the bearing shell would be directly supported by the motorblock.

For instance, the insert may be formed of wrought aluminum alloys of theAl-Cu-Mg type which possess compression yield strengths of between about30 and 38 kg./mm.2, or of extruded magnesium alloy AZSSS containingabout 8% aluminum, l0.5% zinc and 0.15% manganese which in longitudinaland lateral direction has a compression yield strength of about 18kg./mm.2 and in a direction perpendicular to the direction of extrusionreaches a compression yield strength value of 26.5 kg./ mm?. Suchextruded inserts are also preferred because of the greater uniformity oftheir mechanical strength and lack of pipings and pores.

Thus, according to the present invention, an insert is interposedbetween motor block and bearing shell, which insert consists of awrought light metal alloy member or of a copper alloy having a greatercompression yield strength than the light metal cast-ing of the motorblock, and the stress exerted by the crank shaft is distributed over alarger area of the cast light metal motor block.

In addition to wrought magnesium and aluminum alloys, it is alsopossible to form the insert of a cast or wrought copper alloy ofrelatively high compression yield strengths having, for instance, acomposition such as described in Examples I-VII.

Example l 57% Cu, up to 3.0% Ni, up to a combined total of 7.5% of Al,Si, Mn, Fe, Sn, the balance being Zn.

Example Il 10% Al, 4% Fe, 4.5% Ni, up to 3.0% Mn, up to 0.5% Zn, up to acombined total of 0.5% Pb, Sn, Si, the balance being Cu.

Example III Between 57.0 and 59.5% Cu, between 1.0 and 3.0% Pb, thebalance being Zn and the permissible quantities of Fe, Sn, Al, Mn, Ni,Sb.

Example IV Between 62.0 and 65.0% Cu, the balance being Zn t and thepermissible quantities of Fe, Sn, Al, Mn, Ni, Pb, Sb.

Example V Between 56.0 and 61.0% Cu, between 0.2 and 3.0% Mn, between0.4 and 1.3% Al, up to 2.0% Ni, up to 1.5% Fe, up `to 0.5% Sn, up to0.8% Si, up to 1.0% Pb, the balance being Zn.

Example VI Between 56.0 and 61.0% Cu, between 0.2 and 3.0% Mn, between1.3 and 2.5% A1, up to 2.0% Ni, up to 1.5% Fe, up to 0.5% Sn, up to 0.8%Si, up to 1.0% Pb, the balance being Zn.

Example VII Between 1.8 and 2.2% Ni, between 0.5 and 0.8% Si, thebalance being Cu.

Generally, copper alloys with between 1.8 and 2.2% nickel and between0.5 and 0.8% silicon will have a compression yield strength of between35 and 55 kg./ mm2; wrought aluminum alloys with between 2.5 and 5%copper, 0.2 and 2.0% magnesium, 0.3 and 1.5% manganese and up to 1%silicon will have a compression yield strength of between 26 and 38kg./mm.2; and the compression yield strength of wrought magnesium alloyswith between 3 and 9% aluminum, 0.1 and 1.5% zinc and 0.1 and 0.3%manganese will be between 16 and 24 kg./mm.2.

Preferably, inserts of the casting alloys according to Examples I and IIare formed from continuously cast proiiled rods by saw cutsperpendicular to the axis of the rod, while inserts of the wroughtalloys of Examples III-VII are cut from extruded profiles. Inserts orrods formed of the alloy of Example VII may also be heat tempered.

The bearing insert or rst support means according to the presentinvention will receive and carry the crank shaft bearing shell and alsowill contact the cast light met-al motor block, whereby the geometricalconfigurattion of the area of contact -between insert and motor blockwill `be such that the stress exerted by the crank shaft will bereceived by -a larger area of the motor block than would tbe the case ifthe bearing shell would be in direct contact with the motor block.

In view of the relatively high temperature in the operating combustionengine, the insert-forming alloy preferably will be an alloy possessinga relatively great cornpression yield strength at such elevatedtemperatures.

Thus, inserts according to the present invention must consist of analloy having a compression yield strength which is considerably higher,preferably at least 50% higher than the compression yield strength ofthe light metal motor block, and preferably the insert will be formed ofa wrought magnesium 4alloy or a wrought aluminum alloy, or -a copperalloy which may be a cast or a wrought copper alloy which possesses suchrelatively great compression yield strength.

yIn `the case of magnesium alloys, it is lpossible to take advantage ofthe anisotropic grain structure by forming the insert by extrusion insuch a manner that maximum compression yield strengths will be achievedin the direction in which the insert is exposed to maximum stress.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a motor block including crank shaftbearings in accordance with the present invention;

FIGS. 2, 3 and 4 are fragmentary elevational views in cross-sectionillustrating several embodiments of fthe present invention.

lFIG. 5 illustrates in the embodiment of FIG. 4 another manner offastening the insert to the motor block;

FIG. 6 is a perspective view of a profiled rod from -which 4insertsVaccording to the present invention may be c ut; and Y FIGS. 7, 8, 9yand 10 are cross-sectional views of yseveral embodiments of inserts'according -to the present invention.

Referring now to the drawings, and particularly to FIG. 1, motor blocky1 is shown consisting of a cast light metal 4alloy having a relativelylow compression yield strength. Inserts 2 are interposed between motorblock 1 and bearing shells 3. Inserts 2 consist of a wrought magnesiumor aluminum alloy, or of :a copper alloy of relatively -greatcompression yield strength. It can readily be seen that the stressexerted by the crank shaft on bearing shell 3 will be absorbed by alesser upwardly ldirected surface area of insert 2, than the surfaceare-a of motor block `1 to which the stress is transmitted from adownwardly directed surface area of insert 2.

lFIGS. 2, 3 and 4 illustrate different cross-sectional configura-tionsof insert 2, whereby FIG. 4 corresponds to the insert shown in FIG. l.In FlGS. 2 4, reference numeral 1 again denotes the motor block,reference numeral 2 the insert of high compression yield strength andreference numeral 3 the bear-ing shell. In addition, the

crank shaft is indicated by reference numeral 4. It will be seen in eachof FIGS. 2-4 that the stress exerted by crank shaft 4 against bearingshell 3 will be transmitted to a surface area of insert 2 which isconsiderably smaller than the area of contact between insert 2 and motorblock As can be seen in FIG. l and easily deduced from FIGS. 2-4, themotor block is formed in one face thereof with yan elongated recesshaving in a transverse direction parallel to said face a predeterminedmaximum transversal extension. Elongated bearing insert 2 -iits into therecess in motor block 1 Iand is formed -with -an elongated partcylindrical recess in its louter face. The recess in insert -2 has inthe plane of its outer face a maximum transversal extension which issmaller than the predetermined ltransversal extension of the recess inthe motor block. Bearing shell 3 tits into the part cylindrical recessin the outer face of bearing insert 2, and crank shaft 4 is supported bybearing shell 3.

Radii m1 and m2 in FIG. 3 serve to indicate the dif* ference between thesize of the two opposite faces of insert 2 which, respectively, contactmotor block 1 land bearing shell 3; and also -to show that the stressoriginating from crank shaft 1 will be transmitted from insert Z over agreater surface `area of motor block 1 than the surface 'area of insert2 `at which such stress is received from bearing shell 3. f

Insert 2 may be fixed tomotor block 1 in various ways, for instance byshrinking, by casting the motor block in `a mold in which inserts 2 hadbeen previously positioned, or by threaded connection.

FIG. 5 corresponds to FIG. 4 Abut shows in addition screws IS,preferably of light metal, which serve for firmly connecting insert t2with rnotor block 1.

Shrinking may ybe carried out by heating the motor block so las toexpand the recesswhich is to receive the insert, introducing the insertinto the recess and allowing the motor block to cool whereby, due tocontraction, the motor block will firmly grip the insert.

'Ihe same effect may be achieved by severely cooling the insert, .forinstance with liquid air, so as to cause contraction of the insert, `andto introduce the thus contracted insert into the recess of a motor blockwhich is maintained either lat ambient Ior :at elevated temperature.

Upon return of insert and motor block to ambient temperature, it will befound that the insert is -iirmly held in the recess.

The insert may also be arranged in the mold in which the motor Iblock isto be cast and upon subsequent pouring of the molten light metal alloyfor the motor block into the mold, the insert will be embedded in themolten alloy and after solidiiication of the alloy, the insert willfirmly adhere thereto.

FIGS. 8, 9 and 10 yare cross-sectional views of different embodiments ofinserts 2. formed -at their face engaging ymotor block 1 with aplurality of closely spaced axially extending grooves 6, or dove-tailedgrooves 7, or dovetailed projections 8 which will serve for firmlyanchoring the respective insert in the motor block alloy cast about thesame.

VAccording to a preferred embodiment, the face of the insert whicheventually will engage the motor block is coated with a layer of lowmelting or fusing met-al, in the case of inserts marde of wroughtmagnesium alloys, for instance, with a layer of lead, cadmium, tin orpreferably zinc. Upon pouring the molten alloy of the moto-r block intothe mold in which the thus coated insert is arranged, the coating metal,at least partially, will form an alloy with the molten motorblock-forming light metal alloy.

Thus, when casting the motor block in a mold in which the inserts arepositioned, lirm anchoring of the insert i-n the motor block can beenhanced by forming the engaging .surface sof the insert for instance inaccordance with FIGS. 8-10, and/ or by arranging on the engaging surface-of the insert a coating or layer oi a metal adapted to form Aan alloywith the molten light metal alloy which is poured into the mold forforming the motor block.

FIG. 6 illustrates an extruded profiled rod consisting of an[anisotropic magnesium alloy as A285 5 which due to its anisotropicgrain orientation possesses in a direction perpendicular to thedirection in which rod 9 had been extruded, las indicated by the arrow,a particularly great `compression yield strength of about 26.5 lig/mm?.

FIG. 7 is a cross-sectional view of the proled `rod illustrated in FIG.6 in a direction perpendicular to the .axis lof the rod andcorresponding to an end face of an insert cut from rod 9.

Thus, according to the present invention, it is essential that thecompression yield strength of fthe insert is considerably greater thanthat of the material of the motor block, preferably at least 50%greater; and that the insert has ya downwardly directed face in contactwith the motor block having a square area which measured in horizontaldirection is considerably greater, preferably at least twice as great asthe square areameasured in horizontal direction of the upwardly directedface of the insert which contacts the bearing shell.

An economical advantage with respect tothe scrap value of the motorblock is achieved by using for the insert an alloy of a qualitativecompositive which is substantially similar to .that of the motorblock-forming alloy, so that motor block rejects and cuttings accruingduring machining of the cast motor block may be remelted :and used forforming the alloy employed for subsequent casting of motor blocks.

It will be understood that each of the elements described above, or twoor more together, may also nd a useful application in other types 'ofreciprocable engines differing from the types described above.

While the invention has been illustrated and described as embodied inareciprooable combustion engine, .it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of the presentinvention.

tion and, therefore, such adaptations should and 'areintended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed -as new and desired to be secured by Letters Patent is:

1. In a reciprocable combustion engine, in combination, a motor block ofcast light metal having in one face thereof an elongated recess havingin a transverse direction parallel to said face la predetermined maximumtransversal extension and including an elognated insert consistingessentially of an alloy selected from the group consisting of wroughtaluminum alloys, wrought magnesium alloys land copper alloys located insaid recess fitting into the same and formed with a substantiallyelongated part cylindrical recess in its outer face, said recess havingin the plane of said outer face a maximum transverse extension smallerthan said predetermined maximum `transversal extension and thecompression yield strength of said alloy being greater than that of thecast light metal of said motor block; and a bearing shell adapted tosupport a crankshaft fitting into said cylindrical recess in saidinsert, whereby pressure exerted by a crankshaft on said bearing shellwill be distributed upon a surface area of said cast light metal of saidcast motor block which is greater than the area of Contact between saidinsert and said bea-ring shell.

2. ln a reciprocable combustion engine, in combination, a motor block ofcast light metal having in one face thereof an elongated recess havingin a transverse direc- .tion parallel to said face a predeterminedmaximum Itransversal extension and including an elongated insertconsisting essentially of an alloy selected from the group consistinglof wrought aluminum alloys, wrought magnesium alloys and copper alloyslocated in said recess fitting into the same and formed with asubstantially elongated part cylindrical recess in its ou-ter face, saidrecess having in the plane of said outer face a maximum transverseextension smaller than said predetermined maximum transversal extensionand the compression yield strength of said alloy being at least 50%greater than that of the cast light metal of said motor block; and abearing shell adapted to support a crankshaft fitting into saidcylindrical recess in said insert, whereby pressure exerted by acrankshaft on said bearing shell will Ibe distributed upon a surfacearea of said cast .light metal of said cast motor block which is greaterthan the area of contact between said insert and said bearing shell.

3. In a reciprocable combustion engine and the like, in combination, acast motor block formed of a material selected from the group consistingof aluminum and magnesium alloys; a crank shaft; bearing means forsupport- Y ing said crank shaft; andfirst support means rmly attached tosaid -motor block and in contact with said bearing means, said firstsupport means being formed of a material selected from the groupconsisting of wrought aluminum alloys, wrought magnesium alloys andcopper alloys, and having -a compression yield strength superior to thatof said cast motor block, said first support means directly carryingsaid bearing and having a bearing contacting surface of predeterminedarea, and also having a surface portion contacting said cast motor blockand so formed that the stress of said crank shaft is distributed upon asurface area of said cast motor -block which is larger than saidpredetermined area.

4. In a reciprocable combustion engine and the like, in combination, acast motor block formed of a material selected from the group consistingof aluminum and magnesium alloys; a crank shaft; bearing means forsupporting said crank shaft; first support means located between saidbearing means and said cast motor block; threaded means fixing saidfirst support means to said cast motor block, said first support meansbeing formed of a material selected from the group consisting of Wroughtaluminum alloys, wrought magnesium alloys and copper alloys, and havinga compression yield strength superior toy that of said cast motor block,said first support means directly carrying said bearing means and havinga bearing contacting surface of predetermined area, and also having asurface portion larger than said predetermined area and adjacent saidcast motor block and so formed that the stress lof said crank shaft isdistributed upon a surface area of -said cast motor block which islarger than said predetermined area.

5. In a reciprocable combustion engine and the like, in combination, acast motor block formed of a material selected from the group consistingof aluminum and magnesium alloys; a crank shaft; bearing means forsupporting said crank shaft; first support means located between saidbearing means and said cast motor block; said first support means beingshrunk onto said cast motor block, said rst support means being `formedof a material selected from the group consisting of Wrought aluminumalloys, wrought magnesium alloys and copper alloys, and having acompression yield strength superior to that of said cast motor block,said first support means directly carrying said bearing and having abearing contacting surface of predetermined area, and also having asurface portion larger than said predetermined area and adjacent saidcast motor block and so formed that the stress of said crank shaft isdistributed upon a surface area of said cast motor block which is largerthan said predetermined area.

6. In a reciprocable combustion engine and the like, in combination, acast motor block -formed of a light metal alloy selected from ythe groupconsisting of alumi- 'num and magnesium alloys; a crank shaft; bearingmeans for supporting said crank shaft; first support means contactingsaid bearing means and partially embedded in said cast motor block; alayer of fusing metal interposed between and adhering said first supportmeans and said cast motor block to each other, said first support meansbeing formed of a material selected from the group consisting of wroughtaluminum alloys, wrought magnesium alloys and copper alloys, and havinga compression yield strength superior to that of said cast motor block,said first support -means directly carrying said bearing and having abearing contacting surface of predetermined area, and also having asurface portion lar-ger than said predetermined area and adjacent saidcast motor block and so formed that the stress of said crank shaft isdistributed upon a surface area of said cast motor block which is largerthan said predetermined area.

7. In a reciprocable combustion engine and the like, in combination, acast motor block formed of a material selected from the group consistingof aluminum and magnesium alloys; a crank shaft; bearing means forsupporting said crank shaft; first support means carrying said bearingmeans; a layer of fusing metal on said first support means said motorblock being cast about said first support means with said layer offusing metal thereon, said layer of fusing metal adhering said rstsupport means and said motor block to each other and at least aportionof said layer of fusing metal forming an alloy with adjacentportions of said cast motor `block so as to make said first supportmeans integral with said motor block, said first support means beingformed of a material selected Ifrom the group consisting of wroughtaluminum alloys, wrought magnesium alloys and copper alloys, and havinga compression yield strength superior to that of said cast motor block,said first support means directly carrying said bearing and having abearing contacting surface of predetermined area, and also having asurface portion larger than said predetermined area and adjacent saidcast motor block and so formed that the 'stress of said crank shaft isdistributed upon a surface 'said bearing means and said cast motorblock, said irst support means being formed of a wrought magnesiumyalloy having a :compression yield strength superior to Ithat of themagnesium alloy forming said cast motor block and including a coating ofa fusing metal selected from the grou-p consisting of lead, tin,cadmiumand zinc, and being adapted to form au alloy with themagnesiumalloy of said cast motor block said coa-ting being interposed betweenand adhering said first support means and said cast motor block to eachother so as to make said first support means integral with said motorblock, said first support means directly carrying said bearing andhaving a bearing contacting surface of predetermined area, and alsohaving a surface portion facing said cast motor block and so formed thatthe stress of said crank shaft is distributed upon a surface area ofsaid cast motor block which is larger than said predetermined area.

9. In a reciprocable combustion engine and-the like, in combination, acast motor block Iformed of a material selected from the groupconsisting of aluminum and magnesium alloys; a crank shaft; bearingmeans for supporting said crank shaft; and first support means locatedbetween said bea-ring means and said ca-st motor block; means formingpart of said cast motor block and of said first support means forinterlocking the same, said first support means being formed of amaterial selected from the group consisting of wrought aluminum alloys,wrought magnesium alloys and copper alloys, and having a compressionyield strength superior to that of said cast motor block, said firstsupport means directly carrying said bearing and having a bearingcontacting surface of predetermined area, and also having a surfaceportion contacting said cast motor block and so formed that the stress'of the said crank shaft is distributed upon a surface area of said castmotor block which is larger than said predetermined area.

10. In a reciprocable combustion engine and the like, in combination, -acast motor block formed of a magnesium alloy; a crank shaft; bearingmeans for supporting said crank shaft; first support means locatedbetween said bearing means and said cast motor block; means forming partof said cast motor block and of said first support means forinterlocking the same, said first support means being formed of awrought magnesium alloy -having a compression yield strength superior tothat of the magnesium alloy forming said cast motor block; and a coatingof a fusing metal selected from the group consisting of lead, tin,cadmium and zinc, and being adapted to form an alloy with the magnesiumalloy of said cast motor block interposed between and adhering saidfirst support means and said cast motor block to each other, said firstsupport means directly carrying said bearing and having a bearingcontacting surface of predetermined tarea, and also having a surfaceportion facing said cast motor block and so :formed that the stress ofsaid crank shaft is distributed upon surface area of said cast motorIblock which is larger than said predetermined area.

11. In a reciprocable combustion engine and the like, in combination, acast motor block formed of an aluminum alloy containing between 5 and13% silicon and at least one of the metals copper, magnesium andmanganese in a proportion of up to 4% copper, up to 1% magnesium and upto 1% manganese, and having a compression yield strength of up to 6.5kg./.mm.2; a crank shaft; bearing means for supporting said crank shaft;and first support means located between said bearing and said cast motorblock, said first support means being formed of a wrought aluminum alloycontaining between 2.5 and 5% copper, between 0.2 and 2% magnesium,between 0.3 and 1.5% manganese and up to 1% silicon, and having acompression yield strength of between about 26 and 38 kg./mm.2, saidfirst support means directly carrying Isaid bearing and having a bearingcontacting sur-face of predetermined area, and also having a surfaceportion fixed to and contacting said cast motor block and so 10 formedthat thestress of said crank shaft is distributed upon a surface area ofsaid cast motor block which is larger than said predetermined area.

12. In a reciprocable combustion engine and the like,

in combination, a cast motor block formed of an aluminum alloycontaining between 5 and 13% silicon and at least one of the metalscopper, magnesium and manganese in a proportion of up to 4% copper, upto 1% magnesium and up to 1% manganese, and having a compression yieldstrength of up to 6.5 kg./:mm.2; a crank shaft; bearing means forsupporting said crank shaft; :and first support means located betweensaid-'bearing means and Isaid cast motor block, said `first supportmeans being formed of a wrought magnesium alloy containing between 3 and9% aluminum, between 0.1 and l1.5% zinc and between 0.1 and 0.3%manganese, and having a compression yield strength of between about 16and 24 kg./mm.2, said first support means directly carrying said bearingand having avbearing contacting surface of predetermined area, and alsohaving a surface portion fixed to and contacting said cast motor block:and so formed that the stress of said crank shaft is distributed upon asurface area of said cast motor block which is larger than saidpredetermined area.

13. In a reciprocable combustion engine and the like, in combination, acast motor block formed of an aluminum alloy containing between 5 and13% silicon and at least one of the metal-s copper, magnesium andmanganese in a proportion of up to 4% copper, up to 1% magnesium and upto 1% manganese, and having a compression yield strength of up to 6.5`k'g/mm; a crank shaft; bearing means for supporting said crank shaft;and first support means located between said bearing means and said castmotor block, said first support mean-s being formed of a copper alloycontaining between 1.8% and 2.2% nickel and between 0.5 and 0.8%silicon, and having a compression yield strength of between about 35 and55 lig/mm?, said first support means directly carrying said bearing andhaving albearing contacting surface of predetermined area, and alsohaving a surface portion fixed to and contacting said cast motor blockand so formed that the -stress of said crank shaft is distributed upon asur- 'face area of said cast motor block which is larger than saidpredetermined area.

14. VIn a reciprocable combustion engine and the like, in combination, acast motor block formed of a magnesium alloy containing between 5 and10% aluminum, between 0 and 4% zinc, and between 0.1 and 0.5 manganese,`and having a compression yield strength of up to 13 kg./mm.2; a crankshaft; bearing means for sup- Iporting said crank shaft; and firstsupport means located between said bearing means and said cast motorblock, said first support means being formed of a wrought magnesiumalloy containing between 3 and 9% aluminum, between 0.1 and 1.5% zincand between 0.1 and 0.3% manganese, and having a compression yieldstrength of between about 16 and 24 kg./:mm.2, said first support meansdirectly carrying said bearing and having a bearing contacting surfaceof predetermined area, and also having a surface portion fixed to andcontacting said cast motor block and so formed that the stress of saidcrank shaft is distributed upon a surface area of said cast motor blockwhich is larger than said predetermined area.

l5. In a reciprocable combustion engine and the like, in combination, acast motor block formed of a magnesium alloy containing between 5 and10% aluminum, between 0 `and 4% zinc, and between 0.1 and 0.5%manganese, and having a compression yield strength of up to 13 kg./mm.2;a crank shaft; bearing means for supporting said crank shaft; and firstsupport means located between said bearing means and said cast motorblock, said first support means being formed of a wrought aluminum alloycontaining between 2.5 and 5% copper, between 0.2 and 2% magnesium,between 0.3 and 1.5% manganese, and up to 1% silicon, and having acompression yield strength of between about 26 and 38 kg./mm.2, saidfirst support means directly carrying said bearing and having a bearingcontacting surface of predetermined area, and also having a surfaceportion fixed to and contacting said cast motor block and so formed thatthe stress of said crank shaft is distributed upon a surface area ofsaid cast motor block which is larger than said predetermined area.

16. In a reciprocable combustion engine and the like, in combination, acast motor block formed of a magnesium alloy containing between and 10%aluminum, between 0 and 4% zinc, and between 0.1 and 0.5% manganese, andhaving a compression yield strength of up to 13 kg./mm.2; a crank shaft;bearing means for supporting said crank shaft; and rst support meanslocated between said bearing means and said cast motor block, said firstsupport means being formed of a copper alloy containing between 1.8% and2.2% nickel and between 0.5 and 0.8% silicon, and having a compressionyield strength of between about 35 and 55 kg./mm.2, said first supportmeans directly carrying said bearing and having a bearing contactingsurface of predetermined area, and also having a surface portion fixedto and contacting said cast motor block and so formed that the stress ofsaid crank shaft is distributed upon a surface area of said cast motorblock which is larger than said predetermined area.

17. A bearing support structure for reciprocable combustion engines andthe like, comprising, in combination, a motor block of cast light metal;a crank shaft; bearing Imeans 4for supporting said crank shaft; extrudedfirst support means of magnesium alloy directly carrying said bearingmeans and having a bearing contacting surface of predetermined area,said magnesium alloy of said extruded first support means having ananisotropic `grain structure; and second support means forming part ofsaid motor block for carrying said first support means, said firstsupport means having a downwardly directed face fixed to and in contactwith said second support means and having a square area which measuredin hori zontal direction equals at least twice the cross-sectional areaof the bearing supported portion of said crank shaft taken in horizontaldirection Iand through the center thereof so that pressure exerted bysaid crank shaft on said bearing will be distributed upon a surface areaof said second support means which is greater than the predeterminedcontact surface area between said bearing and said first support means,the compression yield strength of said first support means being greaterthan the compression yield strength of said second support means and theanisotropic grain orientation in said first support means being suchthat the same possesses maximum compression yield strength in adirection perpendicular to said downwardly directed face of said firstsupport means contacting said second support means.

18. A bearing support structure for reciprocable combustion engines andthe like, comprising, in combination, a motor block of cast light metal;a crank shaft; bearing means for supporting said crank shaft; extrudedfirst support means directly carrying said bearing means and having abearing contacting surface of predetermined area and consistingessentially of an alloy selected from the group consisting of wroughtaluminum alloys, wrought magnesium alloys and copper alloys; and secondsupport means `forming part of said motor block for carrying said firstsupport means, said first support means having a downwardly directedface fixed to and in contact with said second support means and having asquare area which measured in horizontal direction equals at least twicethe cross-sectional Iarea of the bearing supported portion of said crankshaft taken in horizontal direction and through the center thereof sothat pressure exerted by said crank shaft on said bearing will bedistributed upon a surface area of said second support means which isgreater than the predetermined contact surface area between said bearingand said first support means, the compression yield strength of saidfirst support means being at least 50% greater than the compressionyield strength of said second support means.

19. A bearing support structure for reciprocable combustion engines andthe like, comprising, in combination, a motor block of cast light metal;a crank shaft; bearing means for supporting said crank shaft; firstsupport means directly carrying said bearing means and having a bearingcontacting surface of predetermined area and consisting essentially ofan alloy selected from the group consisting of wrought aluminum alloys,wrought magnesium alloys and copper alloys; and second support meansforming part of said motor block for carrying said first support means,said first support means having a downwardly directed face fixed to andin contact with said second support means and having a square area whichmeasured in horizontal direction equals at least twice thecross-sectional area of the bearing supported portion of said crankshaft taken in horizontal direction and through the center thereof sothat pressure exerted by said crank shaft on said bearing will bedistributed upon a surface area of said second support means which isgreater than the predetermined contact surface area between said bearingand said first support means, the compression yield strength of saidfirst support means being greater than the compression yield strength ofsaid second support means.

References Cited in the file of this patent UNITED STATES PATENTS2,324,676 Butterfield July 20, 1943

1. IN A RECIPROCABLE COMBUSTION ENGINE, IN COMBINATION, A MOTOR BLOCK OFCAST LIGHT METAL HAVING IN ONE FACE THEREOF AN ELONGATED RECESS HAVINGIN A TRANSVERSE DIRECTION PARALLEL TO SAID FACE A PREDETERMINED MAXIMUMTRANSVERSAL EXTENSION AND INCLUDING AN ELONGATED INSERT CONSISTINGESSENTIALLY OF AN ALLOY SELECTED FROM THE GROUP CONSISTING OF WROUGHTALUMINUM ALLOYS, WROUGHT MAGNESIUM ALLOYS AND COPPER ALLOYS LOCATED INSAID RECESS FITTING INTO THE SAME AND FORMED WITH A SUBSTANTIALLYELONGATED PART CYLINDRICAL RECESS IN ITS OUTER FACE, SAID RECESS HAVINGIN THE PLANE OF SAID OUTER FACE A MAXIMUM TRANSVERSE EXTENSION SMALLERTHAN SAID PREDETERMINED MAXIMUM TRANSVERSAL EXTENSION AND THECOMPRESSION YIELD STRENGTH OF SAID ALLOY BEING GREATER THAN THAT OF THECAST LIGHT METAL OF SAID MOTOR BLOCK; AND A BEARING SHELL ADAPTED TOSUPPORT A CRANKSHAFT FITTING INTO SAID CYLINDRICAL RECESS IN SAIDINSERT, WHEREBY PRESSURE EXERTED BY A CRANKSHAFT ON SAID BEARING SHELLWILL BE DISTRIBUTED UPON A SURFACE AREA OF SAID CAST LIGHT METAL OF SAIDCAST MOTOR BLOCK WHICH IS GREATER THAN THE AREA OF CONTACT BETWEEN SAIDINERT AND SAID BEARING SHELL.